A dog clutch is a type of clutch used to couple or lock two components together to transfer rotational power from a driving component to a driven component. For example, dog clutches are often used to couple or lock a driving shaft to a driven shaft, to couple or lock a driving shaft to a gear, and/or to engage one or more torque-transmitting clutches with one or more gears to transfer rotational power from the clutches to the corresponding gears.
Dog clutches are used in many different applications including transmissions of motor vehicles. In general, the transmission of a motor vehicle includes a number of selectively engageable clutches. Selective engagement and/or disengagement of the clutches establishes speed or gear ratios between the transmission input shaft and the transmission output shaft. In particular, shifting from a currently established gear ratio to a new gear ratio generally requires disengaging a clutch (i.e., the “off-going clutch”) associated with the current gear ratio and engaging a clutch (i.e., the “on-coming clutch”) associated with the desired new gear ratio.
Some motor vehicle transmissions include a variable-ratio unit (“variator”) used to provide a continuous variation of transmission ratio rather than a series of predetermined ratios. In such transmissions, known as continuously variable transmissions (CVTs), the variator is coupled between the transmission input shaft and the transmission output shaft via gearing and one or more clutches. In one type of continuously variable transmission, referred to as an infinitely variable transmission (IVT), a zero output speed can be obtained independently of the rotational input speed provided to the transmission by the drive unit in a geared neutral mode. In most infinitely variable transmissions, the variator provides a continuously-varying torque output in each operating mode of the transmission.